[whatwg] Canvas feedback (various threads)

Ian Hickson ian at hixie.ch
Thu Feb 10 20:31:42 PST 2011


On Thu, 10 Feb 2011, Boris Zbarsky wrote:
> On 2/10/11 7:56 PM, Ian Hickson wrote:
> > On Thu, 3 Feb 2011, Boris Zbarsky wrote:
> > > 
> > > It looks like CSS rgba colors with an alpha value of 0 are serialized as
> > > rgba() with "0" as the alpha value. in at least Gecko, Webkit, and
> > > Presto.
> > > 
> > > It also looks like canvas style color with an alpha value of 0 are
> > > serialized as rgba() with "0.0" as the alpha value in Gecko 3.6, Webkit,
> > > and Presto.
> 
> I have to correct myself.  The above is the behavior in _Chrome_, not in 
> all Webkit-based browsers.  In Safari, canvas style colors are 
> serialized as the original string they were set to, apparently (so if 
> you set it to 0.0 you get 0.0 back; if you set it to 0 you get 0 back, 
> and if you set "interoperability" you get "interoperability" back...).

I think you had a typo in your test. As far as I can tell, all 
WebKit-based browsers act the same as Opera and Firefox 3 on this:

   http://software.hixie.ch/utilities/js/canvas/?c.clearRect(0%2C%200%2C%20640%2C%20480)%3B%0Ac.save()%3B%0Atry%20%7B%0A%20%20c.strokeStyle%20%3D%20'red'%3B%0A%20%20c.fillText(c.strokeStyle%2C%2020%2C%2080)%3B%0A%20%20c.strokeStyle%20%3D%20'transparent'%3B%0A%20%20c.fillText(c.strokeStyle%2C%2020%2C%20120)%3B%0A%7D%20finally%20%7B%0A%20%20c.restore()%3B%0A%7D%0A


> An additional data point is that in the IE9 RC you get 0, just like in 
> Firefox 4.

Good to know.


> Which is less interop than it seems (due to Safari's behavior), and 
> about to disappear completely, since both IE9 and Firefox 4 will ship 
> with the 0 instead of 0.0....  :(

Is there no chance to fix this in Firefox 4? It _is_ a regression. :-)

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'


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